Everything You Need to Know About a Garage Door Seal

Is your garage letting in unwanted drafts, dirt, water, or unwelcome rodents (and their droppings!) into your home? There’s a good chance that the problem is your faulty or missing garage door seal. 

Since most garage doors are large, it’s important that they come with a proper weather seal to keep out the unnecessary water, wind, dirt, and pests. It’s important to check if the seals are in good condition from time to time.

There’s also a possibility that the concrete floor or driveway apron under the door may have shifted or cracked — creating large gaps under the door. This, however, happens in extreme cases. Here, standard seals won’t work and you will have to get your garage floor repaired.

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Coming back to weather-sealing a garage door, the process usually involves adding or replacing the bottom door seal and the weatherstripping on the stop molding along the top and sides of the garage door. You may also need to add thin weatherstripping between the door panels in order to make the door airtight.

Want more details on garage door seals? Read on. 

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What is a garage door seal?

A garage door seal, also known as weatherstripping or astragal, is a type of sealing mechanism that closes the gap between the ground and the garage door. If you look carefully, you can find the sealing on all four sides of the door along the edges. 

Its goal is to help you keep out any debris or pests.

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Why is weather sealing important?

A well-installed seal provides optimum insulation as it keeps any moisture from entering — through gaps — into your home. And, it prevents flooding too. Not to forget, the tight seal blocks rodents and bugs.

Most importantly, the easy-to-install garage door bottom seal blocks the cold and hot drafts efficiently. As a result, a garage door weather seal will effectively reduce your home energy bills while protecting your garage and its contents. 

Want to find out if you need to replace your residential garage door seals? Begin by inspecting all sides of the garage door yourself. 

If the bottom weather seal is cracking or fringing (or letting in a noticeable draft from underneath your door, you need to replace your bottom seal as soon as possible. Another sure-shot sign is when you can see daylight from the bottom of the door even when it’s closed.

In case you notice that the seals are buckling off the foundation of the door, the side seals will need replacement.

Once you’ve analyzed the damage, it’s best to hire a professional to take care of the sealing for you and make your garage energy efficient, seamlessly.

Take a look at our Complete Guide on Garage Door Opener Installation

Types of garage door seals

Here are some sealing options for you:

• Garage door bottom seal 

The garage door bottom seal aka door sweep is a strip of vinyl or rubber and is one of the most commonly used weather seals. The long strip attaches to the bottom edge of the garage door — helping your door become flush with the ground. 

Since both vinyl and rubber bottom seals are flexible materials, they easily compress when the door to the garage closes. Thus, sealing the gap along the floor — and keeping out the muck, water, or cold breeze. It’s especially a good choice if you have uneven garage flooring. 

FYI: Most wooden garage doors use a strip-style seal that has angled edges. This seal is used against the front of the door and the floor and is typically installed using galvanized or aluminum roofing nails.

On the other hand, metal garage doors usually have an aluminum channel at the bottom to hold a U-shaped rubber gasket — often known as a T-style or astragal seal. At the time of installation, it simply slides into the two small tracks on the channel. 

Apart from the simple installation, the good thing about U-shaped gaskets is that they are available in different sizes — sealing gaps at different heights.

However, keep in mind that this type of seal is prone to warping and shrinking under extreme moisture and temperature changes. 

Further info? Take a look at a Comprehensive Guide on Garage Door Installation

• Garage door threshold seal 

As the name suggests, a threshold seal sticks directly with an adhesive to the floor underneath the garage door. A threshold seal, unlike a bottom seal, is attached to the floor rather than the door. You can always use both together. In fact, even with a door seal. 

It’s usually constructed from hard rubber or vinyl and comes with a unique peak design that’s the perfect barrier between the garage and any surface water or debris. Opt for a quality seal and it will be durable too. 

It’s a good option if your house’s driveway slopes down towards your garage. Moreover, it helps fill even a large gap below your garage door.

The downside to a threshold seal is that just as it blocks any water from flowing in, it also keeps the water from going out of your garage. If you ever decide to hose out your garage in order to sweep out the dirt or debris, this feature can be quite inconvenient. 

• Garage door stop weatherstripping 

Want to prevent wind and rain from getting into your garage around the sides and top? Install a vinyl or rubber weather stripping onto the wood door stop molding (attached to the door jamb).

Replacing your old, worn stripping — that no longer seals against the door — with new weatherstripping onto your door stops is important.

The installation is easy too. As the weatherstripping comes in rolls, all you have to do is just cut it to the required length with a utility knife. It’s best to use galvanized nails or screws to fix it.

This special type of door-stop molding is made of vinyl with a wood-look molding strip and a flexible weather-seal flange — all in one piece. Such a molding with in-built weatherstripping is a good choice if your garage door has old or damaged door stops. 

As far as the installation goes, you can cut the piece easily using a saw. Just position the door stops parallel to the door face, and push the molding so that the weatherstrip flange compresses against the door. Then, fasten the molding to the door jamb with galvanized or stainless steel siding nails. 

FYI: It’s best to install the top molding first. You can then overlap the ends of the top molding with the side stops.

• Garage door panel weatherstripping

This V-shaped garage door weatherstripping seals the gaps between the individual door panels. A good choice if your house has wooden garage doors with panels that have flat edges.

Here too, the installation is quite simple. Most door panel weatherstripping comes in rolls and is self-adhesive. Simply stick it to the top or bottom edge of each door panel and you’re done! 

Just make sure that when the door closes, the panels compress the weatherstripping — creating an effective seal.

Read more: Garage door panel replacement

• Brush seal

This type of sealing is usually more common on commercial doors such as sheet doors or rolling steel doors. It has thousands of bristles that help to reduce noise while keeping out dust and fumes.

You can choose between light, standard, or heavy-duty brush seals as per your requirement. 

FYI: Apart from the above garage door seals, you can even opt for weather seal kits — available in varying thickness and quantity. Though they may have a higher upfront cost, the price will typically include both hardware and installation charges.

Now that you’re familiar with the types of sealing choices you have, it’s time to evaluate the cost of replacing your old garage door seal. 

Read more: Automatic vs manual garage doors

How much does it cost to replace a garage door seal?

It will cost you approximately $60 to install weatherstripping in a single exterior door. Of course, the overall cost will depend on the type of sealing or weatherstripping you choose and the installation as well as labor charges. 

Read more: Can you paint a garage door?

Conclusion

Installing garage door seals properly is crucial in keeping out the insects, debris, rain, and snow. A good-quality seal will help in closing the gap between the ground and your garage door — providing you optimum insulation.
According to research, sealing the gaps around doors and windows can help save as much as 10 to 15% on your energy bill! No wonder garage door seal is a good investment to make.

Read more: Garage door prices

Written by Ramona Sinha. December 26, 2019

Ramona is a content writer for Kukun. This experienced blogger uses simple and succinct words to decipher the complex phenomenon called life. An avid traveler, she’s a digital nomad at heart and an animal lover from the depths of her soul.